Transmission Media and Equipments

Transmission Media & Equipments

Submitted by: Karan Mathur

INDEX

1. Introduction……………………………………………………………..32. SDH Technology………………………………………………………..4

2.1 Diagram for STM-1 frame structure……………………...……….62.2 Diagram for Synchronous Network Components………………....72.3 SDH/SONET BIT RATES………………………………………...82.4 Network Design……………………………………………………92.5 Introduction strategy for SDH…………………………………….102.6 Future of SDH……………………………………………………..102.7 Diagram for Automatic Protection Switching (APS) (Line Protection)…………………………......................................112.8 Diagram for Automatic Protection Switching (APS)

(Unidirectional Rings)…………………………………………….122.9 Diagram for Automatic Protection Switching (APS)

(BI-Directional Rings)……………………………………….........133. E-Carrier………………………………………………………………...14

3.1 E1………………………………………………………………….143.2 Hierarchy Levels…………………………………………………..15

4. Multiplexing……………………………………………………………..164.1 Categories of Multiplexing………………………………………...16 4.2 Diagram for Time Division Multiplexing………………………... 174.3 Diagram for Wavelength Division Multiplexing…………………. 174.4 CWDM v/s DWDM………………………………………………. 18

5. Sampling(Signal Processing)…………………………………………… 196. Media Connectivity……………………………………………………... 20

6.1 Electrical………………………………………………………….. 206.2 Optical Fiber……………………………………………………… 216.3 Design……………………………………………………………. .226.4 Size Matters…………………………………………………….… 226.5 Ethernet…………………………………………………………… 236.6 Cabling……………………………………………………………. 23

7. Multiplexer/Demultiplexer………………………………………….….. 257.1 XDM-100………………………………………………………… 25 7.2 XDM-1000……………………………………………………….. 267.3 XDM-2000……………………………………………………….. 277.4 BG-20B/20E……………………………………………………... 28

8. Carrier Ethernet Switch/Router………………………………………... 30

INTRODUCTIONThe original telecommunication system was developed for PSTN (Public Switch

Telephone Network) for voice communications. But now communication networks include all types of voice, video and data communication over copper wire, optical

fibers and wireless medium.

With the inception of Internet, increasingly numbers of computer networks are now connected via the Internet. So now the concept of telecommunication system has increased complexity significantly. These systems can be divided into different

types by the information they carry. With this kind of categorization, communication systems can be categorized as long-haul point-to-point links,

distribution networks, MAN (metro area network) and WAN (wide area network).

Now let's examine them one by one.

1. Public Switched Telephone Network (PSTN)

This network connects billions of users by switches, routers or other dedicated connections. It was designed to carry voice only at first, but with enhanced services,

they can carry digital data information as well.

Computers with modems can transmit and receive digital data via the PSTN network with enhanced data services such as DSL.

2. Cable TV systems

CATV is still the biggest player for television broadcasting. But now they are facing competitions from Satellite, DSL video on demand. CATV providers also entered

into data communication market and VoIP services.

3. Data Networks

With modern telecommunication systems, all information are transmitted in digital form. These digital networks can be categorized based on network topology,

switching technology and the communication protocols.

The switching technologies used in modern networks can be categorized as circuit switching and packet switching. Circuit switching is used mostly for voice networks but not very efficient. Packet switching can route data packet according to the least

busy path and it provides a virtual connection.

SDH TECHNOLOGY

Synchronous optical networking (SONET) and Synchronous Digital Hierarchy (SDH), are standardized multiplexing protocols that transfer multiple digital bit streams over optical fiber using lasers or light-emitting diodes (LEDs). Lower rates can also be transferred via an electrical interface. The method was developed to replace the Plesiochronous Digital Hierarchy (PDH) system for transporting larger amounts of telephone calls and data traffic over the same fibre wire without synchronization problems.

Due to SONET's essential protocol neutrality and transport-oriented features, SONET was the obvious choice for transporting Asynchronous Transfer Mode (ATM) frames. It quickly evolved mapping structures and concatenated payload containers to transport ATM connections. In other words, for ATM (and eventually other protocols such as TCP/IP and Ethernet), the internal complex structure previously used to transport circuit-oriented connections is removed and replaced with a large and concatenated frame (such as STS-3c) into which ATM frames, IP packets, or Ethernet are placed.

Both SDH and SONET are widely used today. SONET in the U.S. and Canada and SDH in the rest of the world. Although the SONET standards were developed before SDH, their relative penetrations in the worldwide market dictate that SONET is considered the variation.

Difference from PDH

Synchronous networking differs from PDH in that the exact rates that are used to transport the data are tightly synchronized across the entire network, using atomic clocks. This synchronization system allows entire inter-country networks to operate synchronously, greatly reducing the amount of buffering required between elements in the network.

Both SONET and SDH can be used to encapsulate earlier digital transmission standards, such as the PDH standard, or used directly to support either Asynchronous Transfer Mode (ATM) or so-called Packet over SONET/SDH (POS)

networking. As such, it is inaccurate to think of SDH or SONET as communications protocols in and of themselves, but rather as generic and all-purpose transport containers for moving both voice and data. The basic format of an SDH signal allows it to carry many different services in its Virtual Container (VC) because it is bandwidth-flexible.

The basic unit of transmission

The basic unit of framing in SDH is a STM-1 (Synchronous Transport Module level - 1), which operates at 155.52 Mbit/s. SONET refers to this basic unit as an STS-3c (Synchronous Transport Signal - 3, concatenated), but its high-level functionality, frame size, and bit-rate are the same as STM-1.

SONET offers an additional basic unit of transmission, the STS-1 (Synchronous Transport Signal - 1), operating at 51.84 Mbit/s - exactly one third of an STM-1/STS-3c. That is, in SONET the associated OC-3 signal will be composed of three STS-1s (or, more recently in packet transport, the OC-3 signal will carry a single concatenated STS-3c.) Some manufacturers also support the SDH equivalent: STM-0.

SDH frame

The STM-1 (Synchronous Transport Module level - 1) frame is the basic transmission format for SDH or the fundamental frame or the first level of the synchronous digital hierarchy. The STM-1 frame is transmitted in exactly 125 microseconds, therefore there are 8000 frames per second on a fiber-optic circuit designated OC-3 (optical carrier three). The STM-1 frame consists of overhead and pointers plus information payload. The first 9 columns of each frame make up the Section Overhead and Administrative Unit Pointers, and the last 261 columns make up the Information Payload. The pointers (H1, H2, H3 bytes) identify Administrative Units (AU) within the information payload.

The Section overhead of an STM-1 signal (SOH) is divided into two parts: the Regenerator Section Overhead (RSOH) and the Multiplex Section Overhead (MSOH). The overheads contain information from the system itself, which is used for a wide range of management functions, such as monitoring transmission quality, detecting failures, managing alarms, data communication channels, service channels, etc.

STM–1 frame contains

• 1 octet = 8 bit • Total content : 9 x 270 octets = 2430 octets

• overhead : 8 rows x 9 octets • pointers : 1 row x 9 octets • payload : 9 rows x 261 octets

• Period : 125 μsec • Bitrate : 155.520 Mbit/s (2430 octets x 8 bits x 8000 frame/s )

• payload capacity : 150.336 Mbit/s (2349 x 8 bits x 8000 frame/s)

SYNCHRONOUS NETWORK COMPONENTS

SDH/ SONET BIT RATES

Network Design

Network Topology

The flexibility of SDH can be used to best advantage by introducing a new network topology. Traditional networks make use of mesh and hub (i.e., star) arrangements, but SDH, with the help of DXCs and hub multiplexers, allows these to be used in a much more comprehensive way. SDH also enables these arrangements to be combined with rings and chains of ADMs to improve flexibility and reliability across the core and access areas of a network. Figure 4 shows the basic fragments of network topology that can be combined.

Rings could supply improved services to a high-density business area, a major science park, or a conference/exhibition center. In addition, they may displace multiple local exchanges by multiplexers and fiber connections to a single major exchange for lower costs.

Introduction Strategy for SDH

Depending on the regulatory position and the relative age and demands of different parts of an operator's network, SDH may be introduced first for the following reasons:

• for trunk transmission where line capacity is inadequate or unreliable, such as by introducing 2.5 Gbps optical-line systems

• to provide improved capacity for digital services in an area, such as by introducing rings of ADM

• to give broadband and flexible access to customers over optical fibers where provision of copper pairs is inadequate for the demand, such as by introducing IDLC–type systems (integrated digital loop carrier using remote multiplexers connected to a service switch via optical fibers)

• to provide bandwidth flexibility in the trunk network for provisioning and restoration, by introducing DXC 4n/4 high-order cross-connect switches

• to give time-switched leased lines, other services, and improved utilization of the network or to maximize the availability of specific services; these applications would use ADMs, hubs, or low-order DXC–types such as 4/1 or 1/1

Future of SDH

Almost all new fiber-transmission systems now being installed in public networks use SDH or SONET. They are expected to dominate transmission for decades to come, just as their predecessor PDH has dominated transmission for more than 20 years (and still does in terms of total systems installed). Bit rates in long-haul systems are expected to rise to 40 Gbps soon after the year 2000, at the same time as systems of 155 Mbps and below penetrate more deeply into access networks.

AUTOMATIC PROTECTION SWITCHING (APS)

LINE PROTECTION

UNIDIRECTIONAL RINGS

BI-DIRECTIONAL RINGS

E-CARRIER

The E-carrier standards form part of the Plesiochronous Digital Hierarchy (PDH) where groups of E1 circuits may be bundled onto higher capacity E3 links between telephone exchanges or countries. This allows a network operator to provide a

private end-to-end E1 circuit between customers in different countries that share single high capacity links in between.

In practice, only E1 (30 circuit) and E3 (480 circuit) versions are used. Physically E1 is transmitted as 32 timeslots and E3 512 timeslots, but one is used for framing and typically one allocated for signalling call setup and tear down. Unlike Internet data services, E-carrier systems permanently allocate capacity for a voice call for its entire duration. This ensures high call quality because the transmission arrives with the same short delay (Latency) and capacity at all times.

E1 circuits are very common in most telephone exchanges and are used to connect to medium and large companies, to remote exchanges and in many cases between exchanges. E3 lines are used between exchanges, operators and/or countries, and have a transmission speed of 34.368 Mbit/s.

E1

An E1 link operates over two separate sets of wires, usually twisted pair cable. A nominal 3 Volt peak signal is encoded with pulses using a method that avoids long periods without polarity changes. The line data rate is 2.048 Mbit/s (full duplex, i.e. 2.048 Mbit/s downstream and 2.048 Mbit/s upstream) which is split into 32 timeslots, each being allocated 8 bits in turn. Thus each timeslot sends and receives an 8-bit sample 8000 times per second (8 x 8000 x 32 = 2,048,000). This is ideal for voice telephone calls where the voice is sampled into an 8 bit number at that data rate and reconstructed at the other end. The timeslots are numbered from 0 to 31.

One timeslot (TS0) is reserved for framing purposes, and alternately transmits a fixed pattern. This allows the receiver to lock onto the start of each frame and match up each channel in turn. The standards allow for a full Cyclic Redundancy Check to be performed across all bits transmitted in each frame, to detect if the circuit is losing bits (information), but this is not always used. Unlike the earlier T-carrier systems developed in North America, all 8 bits of each sample are available for each call. This allows the E1 systems to be used equally well for circuit switch data calls, without risking the loss of any information.

Hierarchy levels

The PDH based on the E0 signal rate is designed so that each higher level can multiplex a set of lower level signals. Framed E1 is designed to carry 30 E0 data channels + 1 signalling channel, all other levels are designed to carry 4 signals from

the level below. Because of the necessity for overhead bits, and justification bits to account for rate differences between sections of the network, each subsequent level has a capacity greater than would be expected from simply multiplying the lower level signal rate (so for example E2 is 8.448 Mbit/s and not 8.192 Mbit/s as one might expect when multiplying the E1 rate by 4).

Note, because bit interleaving is used, it is very difficult to demultiplex low level tributaries directly, requiring equipment to individually demultiplex every single level down to the one that is required.

Signal Rate

E0 64 kbit/s

E1 2.048 Mbit/s

E2 8.448 Mbit/s

E3 34.368 Mbit/s

E4 139.264 Mbit/s

MULTIPLEXING

In telecommunications and computer networks, multiplexing (also known as muxing) is a process where multiple analog message signals or digital data streams are combined into one signal over a shared medium. The aim is to share an expensive resource. For example, in telecommunications, several phone calls may be transferred using one wire. It originated in telegraphy, and is now widely applied in communications.

The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred. A reverse process, known as demultiplexing, can extract the original channels on the receiver side.

A device that performs the multiplexing is called a multiplexer (MUX), and a device that performs the reverse process is called a demultiplexer (DEMUX).

Inverse multiplexing (IMUX) has the opposite aim as multiplexing, namely to break one data stream into several streams, transfer them simultaneously over several communication channels, and recreate the original data stream.

Categories of multiplexing

The two most basic forms of multiplexing are time-division multiplexing (TDM) and frequency-division multiplexing (FDM), both either in analog or digital form. FDM requires modulation of each signal.

In optical communications, FDM is referred to as wavelength-division multiplexing (WDM).

Variable bit rate digital bit streams may be transferred efficiently over a fixed bandwidth channel by means of statistical multiplexing, for example packet mode communication. Packet mode communication is an asynchronous mode time-domain multiplexing, which resembles but should not be considered as time-division multiplexing.

Digital bit streams can be transferred over an analog channel by means of code-division multiplexing (CDM) techniques such as frequency-hopping spread spectrum (FHSS) and direct-sequence spread spectrum (DSSS).

TIME DIVISION MULTIPLEXING

WAVELENGTH DIVISION MULTIPLEXING

CWDM vs DWDM

CHARACTERISTISC COARSE WDM DENSE WDM

CHANNEL SPACING LARGE 2500 Ghz

(20 nm)

SMALL 200 Ghz

(0.8 nm)NUMBER OF BANDS USED O;E;S;C AND L C and L

COST PER CHANNEL LOW HIGH

NUMBER OF CHANNEL DELIVERED

17 TO 18 HUNDREDS OF CHANNELS POSSIBLE

AGGREGATE FIBRE CAPACITY

20 TO 40 Gbps 100 TO 1000 Gbps

TRANSMISSION DISTANCE UPTO 70 Km UPTO 900 Km

BEST APPLICATION SHORT-HAUL LONG HAUL

SAMPLING(signal processing)

In signal processing, sampling is the reduction of a continuous signal to a discrete signal. A common example is the conversion of a sound wave (a continuous-time signal) to a sequence of samples (a discrete-time signal).

A sample refers to a value or set of values at a point in time and/or space.

Theory

Let x(t) be a continuous signal which is to be sampled, and that sampling is performed by measuring the value of the continuous signal every T seconds, which is called the sampling interval. Thus, the sampled signal x[n] given by:

x[n] = x(nT), with n = 0, 1, 2, 3, ...

The sampling frequency or sampling rate fs is defined as the number of samples obtained in one second, or fs = 1/T. The sampling rate is measured in hertz or in samples per second.

We can now ask: under what circumstances is it possible to reconstruct the original signal completely and exactly (perfect reconstruction)?

A partial answer is provided by the Nyquist–Shannon sampling theorem, which provides a sufficient (but not always necessary) condition under which perfect reconstruction is possible. The sampling theorem guarantees that bandlimited signals (i.e., signals which have a maximum frequency) can be reconstructed perfectly from their sampled version, if the sampling rate is more than twice the maximum frequency. Reconstruction in this case can be achieved using the Whittaker–Shannon interpolation formula.

The frequency equal to one-half of the sampling rate is therefore a bound on the highest frequency that can be unambiguously represented by the sampled signal. This frequency (half the sampling rate) is called the Nyquist frequency of the sampling system. Frequencies above the Nyquist frequency fN can be observed in the sampled signal, but their frequency is ambiguous. That is, a frequency component with frequency f cannot be distinguished from other components with frequencies NfN + f and NfN – f for nonzero integers N. This ambiguity is called aliasing. To

handle this problem as gracefully as possible, most analog signals are filtered with an anti-aliasing filter.

MEDIA CONNECTIVITY

Electrical

All power line communications systems operate by impressing a modulated carrier signal on the wiring system. Different types of powerline communications use different frequency bands, depending on the signal transmission characteristics of the power wiring used. Since the power wiring system was originally intended for transmission of AC power, in conventional use, the power wire circuits have only a limited ability to carry higher frequencies. The propagation problem is a limiting factor for each type of power line communications. A new discovery called E-Line that allows a single power conductor on an overhead power line to operate as a waveguide to provide low attenuation propagation of RF through microwave energy lines while providing information rate of multiple Gbps is an exception to this limitation.

Data rates over a power line communication system vary widely. Low-frequency (about 100-200 kHz) carriers impressed on high-voltage transmission lines may carry one or two analog voice circuits, or telemetry and control circuits with an equivalent data rate of a few hundred bits per second; however, these circuits may be many miles long. Higher data rates generally imply shorter ranges; a local area network operating at millions of bits per second may only cover one floor of an office building, but eliminates installation of dedic

Any current-carrying conductor, including a cable, radiates an electromagnetic field. Likewise, any conductor or cable will pick up energy from any existing electromagnetic field around it. These effects are often undesirable, in the first case amounting to unwanted transmission of energy which may adversely affect nearby equipment or other parts of the same piece of equipment; and in the second case, unwanted pickup of noise which may mask the desired signal being carried by the cable, or, if the cable is carrying power-supply or control voltages, pollute them to such an extent as to cause equipment malfunction.

The first solution to these problems is to keep cable lengths short, since pick up and transmission are essentially proportional to the length of the cable. The second solution is to route cables away from trouble. Beyond this, there are particular cable designs that minimise electromagnetic pickup and transmission. Three of the principal design techniques are shielding, coaxial geometry, and twisted-pair geometry.

Coaxial design helps to further reduce low-frequency magnetic transmission and pickup. In this design the foil or mesh shield is perfectly tubular – ie., with a circular cross section – and the inner conductor (there can only be one) is situated exactly at its centre. This causes the voltages induced by a magnetic field between the shield and the core conductor to consist of two nearly equal magnitudes which cancel each other.

Optical fiber

An optical fiber (or fibre) is a glass or plastic fiber that carries light along its length. Fiber optics is the overlap of applied science and engineering concerned with the design and application of optical fibers. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communications. Fibers are used instead of metal wires because signals travel along them with less loss, and they are also immune to electromagnetic interference. Fibers are also used for illumination, and are wrapped in bundles so they can be used to carry images, thus allowing viewing in tight spaces. Specially designed fibers are used for a variety of other applications, including sensors and fiber lasers.

Light is kept in the core of the optical fiber by total internal reflection. This causes the fiber to act as a waveguide. Fibers which support many propagation paths or transverse modes are called multi-mode fibers (MMF), while those which can only support a single mode are called single-mode fibers (SMF). Multi-mode fibers generally have a larger core diameter, and are used for short-distance communication links and for applications where high power must be transmitted. Single-mode fibers are used for most communication links longer than 550 metres (1,800 ft).

The process of communicating using fiber-optics involves the following basic steps: Creating the optical signal involving the use of a transmitter, relaying the signal along the fiber, ensuring that the signal does not become too distorted or weak, receiving the optical signal, and converting it into an electrical signal

Design

In practical fibers, the cladding is usually coated with a tough resin buffer layer, which may be further surrounded by a jacket layer, usually plastic. These layers add strength to the fiber but do not contribute to its optical wave guide properties. Rigid fiber assemblies sometimes put light-absorbing ("dark") glass between the fibers, to prevent light that leaks out of one fiber from entering another. This reduces cross-talk between the fibers, or reduces flare in fiber bundle imaging applications.[1]

Size Matters

Fiber, as we said, comes in two types, singlemode and multimode. Except for fibers used in specialty applications, singlemode fiber can be considered as one size and

type. If you deal with long haul telecom or submarine cables, you may have to work with specialty singlemode fibers.

Multimode fibers originally came in several sizes, optimized for various networks and sources, but the data industry standardized on 62.5 core fiber in the mid-80s (62.5/125 fiber has a 62.5 micron core and a 125 micron cladding.) Recently, as gigabit and 10 gigabit networks have become widely used, an old fiber has been revived. The 50/125 fiber was used from the late 70s with lasers for telecom applications before singlemode fiber became available. It offers higher bandwidth with the laser sources used in the gigabit LANs and can go longer distances. While it still represents a smaller volume than 62.5/125, it is growing.

Ethernet

Ethernet over twisted pair refers to the use of cables that contain insulated copper wires twisted together in pairs for the physical layer of an Ethernet network—that is, a network in which the Ethernet protocol provides the data link layer. Other Ethernet cable standards use coaxial cable or optical fiber. There are several different standards for this copper-based physical medium. The most widely used are 10BASE-T, 100BASE-TX, and 1000BASE-T (Gigabit Ethernet), running at 10 Mbit/s, 100 Mbit/s (also Mbps or Mbs-1), and 1000 Mbit/s (1 Gbit/s) respectively. These three standards all use the same connectors. Higher speed implementations nearly always support the lower speeds as well, so that in most cases different generations of equipment can be freely mixed. They use 8 position modular connectors, usually called RJ45 in the context of Ethernet over twisted pair. The cables usually used are four-pair or above twisted pair cable. Each of the three standards support both full-duplex and half-duplex communication. According to the standards, they all operate over distances of up to 100 meters.

The common names for the standards derive from aspects of the physical media. The number refers to the theoretical maximum transmission speed in megabits per

second (Mbit/s). The BASE is short for baseband, meaning that there is no frequency-division multiplexing (FDM) or other frequency shifting modulation in use; each signal has full control of wire, on a single frequency. The T designates twisted pair cable, where the pair of wires for each signal is twisted together to reduce radio frequency interference and crosstalk between pairs (FEXT and NEXT). Where there are several standards for the same transmission speed, they are distinguished by a letter or digit following the T, such as TX. Some higher-speed standards use coaxial cable, designated by CX.

Cabling

Twisted-pair Ethernet standards are such that the majority of cables can be wired "straight-through" (pin 1 to pin 1, pin 2 to pin 2 and so on), but others may need to be wired in the "crossover" form (receive to transmit and transmit to receive).

It is conventional to wire cables for 10 or 100 Mbit/s Ethernet to either the T568A or T568B standards. Since these standards differ only in that they swap the positions of the two pairs used for transmitting and receiving (TX/RX), a cable with TIA-568A wiring at one end and TIA-568B wiring at the other is referred to as a crossover cable. The terms used in the explanations of the 568 standards, tip and ring, refer to older communication technologies, and equate to the positive and negative parts of the connections.

A 10BASE-T transmitter sends two differential voltages, +2.5 V or −2.5 V.

100BASE-TX follows the same wiring patterns as 10BASE-T but is more sensitive to wire quality and length, due to the higher bit rates.

A 100BASE-TX transmitter sends 3 differential voltages, +1 V, 0 V, or −1 V[1].

1000BASE-T uses all four pairs bi-directionally and the standard includes auto MDI-X; however, implementation is optional. With the way that 1000BASE-T implements signaling, how the cable is wired is immaterial in actual usage. The standard on copper twisted pair is IEEE 802.3ab for Cat 5e UTP, or 4D-PAM5; four dimensions using PAM (pulse amplitude modulation) with five voltages, −2 V, −1 V, 0 V, +1 V, and +2 V [2] While +2 V to −2 V voltage may appear at the pins of the line driver, the voltage on the cable is nominally +1 V, +0.5 V, 0 V, −0.5 V and −1 V[3].

A 10BASE-T transmitter sends two differential voltages, +2.5 V or −2.5 V.

100BASE-TX follows the same wiring patterns as 10BASE-T but is more sensitive to wire quality and length, due to the higher bit rates.

A 100BASE-TX transmitter sends 3 differential voltages, +1 V, 0 V, or −1 V[1].

1000BASE-T uses all four pairs bi-directionally and the standard includes auto MDI-X; however, implementation is optional. With the way that 1000BASE-T implements signaling, how the cable is wired is immaterial in actual usage. The standard on copper twisted pair is IEEE 802.3ab for Cat 5e UTP, or 4D-PAM5; four dimensions using PAM (pulse amplitude modulation) with five voltages, −2 V, −1 V, 0 V, +1 V, and +2 V [2] While +2 V to −2 V voltage may appear at the pins of the line driver, the voltage on the cable is nominally +1 V, +0.5 V, 0 V, −0.5 V and −1 V[3].

Multiplexer/DemultiplexerIn electronics, a multiplexer or mux (occasionally the term muldex or muldem[1] is also found, for a combination multiplexer-demultiplexer) is a device that performs multiplexing; it selects one of many analog or digital input signals and forwards the selected input into a single line. A multiplexer of 2n inputs has n select bits, which are used to select which input line to send to the output.

An electronic multiplexer makes it possible for several signals to share one device or resource, for example one A/D converter or one communication line, instead of having one device per input signal. In electronics, a demultiplexer (or demux) is a device taking a single input signal and selecting one of many data-output-lines, which is connected to the single input. A multiplexer is often used with a complementary demultiplexer on the receiving end.

In telecommunications, a multiplexer is a device that combines several input information signals into one output signal, which carries several communication channels, by means of some multiplex technique. A demultiplexer is in this context a device taking a single input signal that carries many channels and separates those over multiple output signals.

In telecommunications and signal processing, an analog time division multiplexer (TDM MUX) may take several samples of separate analogue signals and combine

them into one pulse amplitude modulated (PAM) wide-band analogue signal. Alternatively, a digital TDM multiplexer may combine a limited number of constant bit rate digital data streams into one data stream of a higher data rate, by forming data frames consisting of one timeslot per channel.

In telecommunications, computer networks and digital video, a statistical multiplexer may combine several variable bit rate data streams into one constant bandwidth signal, for example by means of packet mode communication. An inverse multiplexer may utilize several communication channels for transferring one signal.

XDM-100

An economical, highly-scalable Metro Access multiservice aggregation platform with add-on CWDM capability. Ideal for developing organizations, this modular shelf accepts a large variety of interfaces, supports a wide range of redundant/non-redundant configurations and covers E1/DS-3 to STM-16/OC-48 It supports Carrier Class Ethernet and CWDM.

XDM-100 works in concert with the entire ECI portfolio to provide a complete solution tied together by ECI's 1Net architectural framework

Features

• Full non-blocking 30 Gbps matrix • Supports 10/100BaseT and Gigabit Ethernet switching for data services

Redundant multiservice ADM 4/16 • Scalable STM4/16 traffic aggregation; multi-ring, point-2-point topology • High scalability and modularity, versatility of interfaces and services

Benefits

• Cost-effective pay-as-you-grow solution for access networks • Fully redundant architecture • Supports extended ambient temperature ranges

XDM-1000

The XDM®-1000 is a future-proof converged multiservice optical platform optimized for metro and regional networks. The XDM-1000 offers unique convergence of SDH/SONET, TDM/ATM, Carrier Ethernet/MPLS, and all-range WDM/OTN ROADM on a single platform, leading the P-OTS’ (Packet Optical Transport System) market segment. With a 100% non-blocking E1 to STM-64 switching matrix of 120 Gbps, and a variety of interfaces from E1 through STM-1/4/16/64 and FE/GE/10 GE up to 40/80 DWDM channels, it fits a broad range of applications and services, including mobile backhaul, business, MSOs, CoCs, and residential triple play. With extensive support of both data (L1, L2, EoS, MPLS) and optics (C/DWDM, WSS ROADM), it supports a smooth migration path to packets-based networks.

FEATURES

• Unique convergence of SDH/SONET, TDM/ATM, Carrier Ethernet/MPLS and all-range WDM/OTN ROADM on a single platform – leading the P-OTS (Packet Optical Transport System) platform

• Hybrid and scalable platform for services – PDH (E1, E3, DS-3), SDH/SONET (STM-1/4/16/64/OC-3/12/48/192), data (ATM, FE/GE (Ethernet L1, L2, MPLS))

• Advanced optics – In-service scalability to handle terabit traffic via C/DWDM and support state of the art 10 degree ROADM for pure optical networks

• Full non-blocking 120 Gbps LO/HO matrix, from E1 to STM-64 • Topology agnostic – enabling mesh, ring, multi-ring, star, and point-to-point

topologies • Advanced Ethernet services – E-Line (point-to-point), E-LAN (multipoint-

to-multipoint), E-Tree (rooted-multipoint) • ASON/GMPLS support • Build as you grow® modular design

BENEFITS

• Massive traffic concentrator • Leverages existing infrastructure to deliver new services • Reduces the risks associated with rolling out new services • Smooth migration to carrier class Ethernet services over optical transport

networks • Uses same HW among various family members • Carrier class protection, restoration, and resiliency

XDM-2000

Optimized for pure DWDM and converged optical applications, the XDM-2000 is designed for metro and metro-regional cores. A high density DWDM platform providing intelligent sublambda grooming and optimum wavelength utilization, transporting up to 1.6 Tbps and integrating the most advanced optical units with varied interfaces and an ultra high-capacity matrix.

XDM-2000 works in concert with the entire ECI portfolio to provide a complete solution tied together by ECI's 1Net architectural framework

Features

• Delivers all services from 50 Mbps to 10 Gbps to 80 DWDM channels• Full non-blocking 120 Gbps matrix, from E-1 to STM-64• Compact size: 19" or 23" rack mounting

Benefits

• Suitable for mesh, ring, multi-ring, star, and point-2-point topologies

• Complete DWDM platform with sublambda grooming for metro-core applications

BG-20B/20E

The BG-20/20E is a unique, fully integrated SDH multiplexer designed for access networks and enterprise CPEs, supporting a wide-ranging and attractive combination of cost-effective high-performance Carrier-Class Ethernet , SDH, PDH, and legacy PCM services. Its scalable architecture implements network expansion, helping provide new services while tailoring solutions to the needs of medium and large enterprises.

Features

• Multiple Cross-connect (DXC 1/0) capabilities • DS0 to full SDH 4/3/1 with a rich mix of low bitrate interfaces • Supports Carrier Class Ethernet Services with Ethernet L1 and L2 and

MPLS-based services • SDH reliability, security, and management of data services

• Multiple PCM interfaces: POTS, VF interfaces, V24, V35/V11, Ethernet over PDH (NxE1), Nx64K

Benefits

• Profit booster with tiered configurable services over existing infrastructure • Supports a range of services from POTS to carrier class Ethernet • Seamless bandwidth scalability from STM-1 to STM-4 • Huge savings via minimal power usage, reduced footprint, remote

management

Carrier Ethernet Switch/Router

An evolution is underway in today's metro networks. Market trends are driving a transition from traditional services to new services that offer lower-cost bandwidth and greater connectivity. As such, Ethernet - with its familiarity, simplicity, low cost and greater economies of scale - has become the preferred delivery platform for next-generation services. However, current Ethernet switch/routers often lack the performance, reliability, and density required in carrier environments.With its 9000 Family of Carrier Ethernet switch/routers, ECI combines its expertise in metro transport with advanced IP/MPLS software to deliver a Carrier Ethernet solution with the manageability, reliability, and deterministic performance that carriers require.

With ECI's 9000 Family, carriers now have a clear path for transforming their metro infrastructure into a cost-efficient packet-optical network that efficiently supports any Ethernet or IP service with same reliability and performance characteristics found in transport networks. The 9000 Family enables operators to converge disparate networks and collapse layers of complexity, reducing costs and streamlining service delivery.

The 9000 Family provides an end-to-end Carrier Ethernet metro solution from customer premises to the metro core via two series of products - the 9700 and the 9200. Both series are integrated with LightSoft, ECI's network multilayer management system for TDM, packet, and optical networks, and have been tested and certified by the Metro Ethernet Forum (MEF) to meet MEF standards for service delivery over Gigabit Ethernet and 10 Gigabit Ethernet interfaces.

Benefits:

• Smooth evolution to next-generation networks – lower TCO with seamless transition from existing infrastructure to next-generation networks

• Ease of management – point-and-click service provisioning, intelligent OAM, robust performance management, and sophisticated IP/MPLS software enabling self-healing and self-optimization

• Network simplification – true convergence for business, residential, and mobile services with simultaneous support of Layer 2 and Layer 3 services and integration of packet and optical technologies

• Real carrier-class availability – built specifically with a transport mindset leveraging ECI’s vast carrier-grade expertise to Carrier Ethernet

• Service-enabling intelligence – the most sophisticated QoS models available on a Carrier Ethernet switch/router